Phosphatase and tensin homolog immunohistochemical staining and clinical criteria for Cowden syndrome in patients with trichilemmoma or associated lesions.

[cowden syndrome]

Trichilemmomas and mucocutaneous papillomatous papules are associated with Cowden syndrome (CS ). Germline Phosphatase and tensin homolog (PTEN ) mutations have been identified in 34 % to 80 % of those meeting clinical criteria for CS . PTEN expression has not been well evaluated in large numbers of trichilemmoma . We investigated clinical criteria for CS in trichilemmoma patients and studied PTEN staining to determine how often patients with trichilemmoma have CS and whether PTEN staining is useful . About 102 cases of trichilemmoma or associated lesions from 95 patients were collected . Clinical histories were reviewed to investigate the incidence of CS using International Cowden Consortium operational criteria for diagnosis of CS , version 2000 . PTEN staining was performed and graded for intensity and percentage . Although 1 patient had 3 trichilemmoma or associated lesions , and 5 had 2 trichilemmoma or associated lesions , none of 95 patients met clinical criteria for a diagnosis of CS . Twelve of the 89 cases available for staining (13 .5 %) showed decreased PTEN . Of these , the demographic , clinical , and pathological features were not significantly different compared with PTEN intact cases . None of the cases from the 6 patients with more than 1 trichilemmoma or associated lesions showed decreased PTEN staining . We thus conclude that the likelihood of a clinical diagnosis of CS among patients with a solitary or only a few trichilemmoma is extremely low . PTEN expression is decreased in some sporadic trichilemmomas or associated lesions . This is the largest study investigating clinical history and PTEN staining in patients with trichilemmoma or associated lesions . Because none of our patients met clinical diagnostic criteria for CS , the direct correlation of PTEN in CS and sporadic trichilemmoma remains unclear .